1. Field of the Invention
The present invention relates to ladder constructions, and, more particularly, to a kit for converting a conventional extension ladder into a stepladder.
2. Description of the Prior Art
There have been previous inventions for convertible ladders, but the prior art does not teach a kit for converting a ladder in the manner disclosed in the instant application.
U.S. Pat. No. 4,256,200, issued on Mar. 17, 1981, to Gilbert Loix, discloses a stepladder which can be transformed into an extension ladder. The instant invention is distinguishable in that it is a kit for converting a ladder, not a ladder itself, and that it uses support braces for the stepladder mode that connect opposed side rails or rungs on the same level but opposite sides of the ladder.
U.S. Pat. No. 4,284,171, issued on Aug. 18, 1981, to Graham Owen, discloses a convertible ladder that can be set up as an extension ladder, a stepladder or a trestle. The instant invention is distinguishable in that it is a kit for converting a ladder, not a ladder itself, it does not have a trestle mode or a plank member for a trestle, and its support braces are connected to side rails of the ladder by encircling braces or with rods inserted through hollow rungs.
U.S. Pat. No. 4,448,282, issued on May 15, 1984, to Rnedi Giezendanner, discloses a multipurpose ladder construction which can be configured as a stepladder, an extension ladder, or a wheeled hand truck. The instant invention is distinguishable in that it is a kit for converting a conventional extension ladder, not a ladder itself, it does not have wheels, and when it has been installed to convert an extension ladder into a stepladder, the opposite sides of the ladder are held together by support braces between the side rails or rungs.
U.S. Pat. No. 4,469,193, issued on Sep. 4, 1984, to Joseph F. Rumsey, Jr., discloses a utility ladder that can be used either as an extension ladder, stepladder or stool. The instant invention is distinguishable in that it is a kit for converting a ladder, not a ladder itself, and when it has been installed to convert an extension ladder into a stepladder, the opposite sides of the ladder are held together by a novel support brace arrangement.
U.S. Pat. No. 4,947,960, issued on Aug. 14, 1990, to Guenther Krause, discloses a connecting element for connecting upper and lower parts of an extension ladder. It may be distinguished from the instant invention, in that the support brace of the latter encloses the entire circumference of a side rail or rung, or else connects to a rod going through a hollow rung.
U.S. Pat. No. 5,158,151, issued on Oct. 27, 1992, to Wan-Li Chang, discloses a bidirectionally foldable stepladder, which does not convert to an extension ladder.
U.S. Pat. No. 5,353,892, issued on Oct. 11, 1994, to Feng-Hui Lu, discloses a ladder joint for a folding collapsible ladder, in which opposite sides of the ladder are not connected by support braces.
British Patent No. 995,495, published on Jun. 16, 1965, discloses a ladder convertible from step to extending. The instant invention is distinguishable in that it is a kit for converting a ladder, not a ladder itself, and when it has been installed to convert an extension ladder into a stepladder, the opposite sides of the ladder are held together by a novel support brace assembly.
French Patent No. 2 435 596, published on Apr. 4, 1980, discloses a ladder convertible from step to extending, in which the connection between rungs on opposite sides in the stepladder mode is flexible, rather than rigid as in the instant invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.